Tailor Chetna, Ashby W Spencer, Gorassini Donald R, Lownie Stephen P, Walsh Kimberley, Pelz David, Hammond Robert R
1LMC Diabetes and Endocrinology, Ottawa.
Departments of2Pathology.
J Neurosurg. 2019 Mar 15;132(4):1140-1146. doi: 10.3171/2018.12.JNS182244. Print 2020 Apr 1.
Endovascular approaches have evolved from a technique practiced at very few centers to a widely available option in the management of arteriovenous malformations (AVMs) of the central nervous system. Embolization can be employed as definitive therapy or as an adjunct to surgical excision. A wide variety of embolic agents have been successfully developed and used in the clinical setting. In addition to facilitating vascular occlusion, embolic agents induce a number of reactive and destructive changes in vessel walls and the surrounding tissue. However, studies examining the pathological changes induced by different embolic agents and varying times of exposure are scarce. The goal of the present study was to compare embolic agents and time of exposure on the pathology in excised specimens.
The records of the Department of Pathology at the London Health Sciences Centre were searched for embolized AVMs for the 35-year period 1980-2015. All cases were reevaluated for clinical and technical variables and standardized histopathological findings. Cases were grouped by embolic agent, volume of agent used, and time to excision.
A total of 101 specimens were identified. Embolic agents were invariably associated with a range of pathological findings, some of which may affect the integrity of vessel walls or the reestablishment of flow, thrombosis, acute and chronic inflammatory changes, angionecrosis, extravasation, and recanalization. The type of embolic agent did not predict differences in the incidence or severity of histopathological changes. Larger volumes of embolic agent were associated with a greater proportion of vessels containing embolic material. AVMs excised early (< 1 week postembolization) contained more acute vasculitis, while those excised later (≥ 1 week postembolization) were more likely to exhibit recanalization and foreign body giant cell infiltrates.
Embolic agents induce a predictable range and temporal progression of pathological changes in cerebral AVMs. The embolic agents studied are indistinguishable in terms of the range and frequency of pathological reactions induced. Greater volumes of embolic agent are associated with more abundant agent within the lesion, but the proportion of vessels and vascular cross-sectional areas containing agent is small. Several changes are significantly associated with time postembolization. Acute vasculitis is a more common finding in the 1st week, while recanalization and foreign body-type granulomatous inflammation are more common at 1 week and beyond.
血管内治疗方法已从少数几个中心开展的一项技术发展成为中枢神经系统动静脉畸形（AVM）治疗中广泛应用的一种选择。栓塞可作为确定性治疗或手术切除的辅助手段。多种栓塞剂已成功研发并应用于临床。除了促进血管闭塞外，栓塞剂还会在血管壁和周围组织中引发一系列反应性和破坏性变化。然而，研究不同栓塞剂及不同暴露时间所诱导的病理变化的研究较少。本研究的目的是比较栓塞剂及暴露时间对切除标本病理的影响。
检索伦敦卫生科学中心病理科1980年至2015年35年间栓塞AVM的记录。对所有病例重新评估临床和技术变量以及标准化组织病理学结果。病例按栓塞剂、所用栓塞剂体积和切除时间分组。
共鉴定出101个标本。栓塞剂总是与一系列病理结果相关，其中一些可能影响血管壁完整性或血流重建、血栓形成、急性和慢性炎症变化、血管坏死、渗漏和再通。栓塞剂类型不能预测组织病理学变化的发生率或严重程度差异。更大体积的栓塞剂与含有栓塞材料的血管比例更高相关。早期切除（栓塞后<1周）的AVM含有更多急性血管炎，而后期切除（栓塞后≥1周）的AVM更可能出现再通和异物巨细胞浸润。
栓塞剂在脑AVM中诱导出可预测的一系列病理变化及时间进程。所研究的栓塞剂在诱导的病理反应范围和频率方面无明显差异。更大体积的栓塞剂与病变内更丰富的栓塞剂相关，但含有栓塞剂的血管比例和血管横截面积较小。一些变化与栓塞后时间显著相关。急性血管炎在第１周更常见，而再通和异物型肉芽肿性炎症在１周及以后更常见。
